Blower Unit for Vehicle

ABSTRACT

A blower unit for generating air for cooling a heat exchanger includes a plurality of blowers, a single motor, a driving shaft, gears, gear boxes and a joint. The blowers are arranged in parallel with each other with respect to a flow of air passing through the heat exchanger. The driving shaft extends from the motor and is connected to rotation shafts of the blowers through the gears. The gear boxes house the gears therein and support the driving shaft and the rotation shafts of the blowers to be rotatable. The driving shaft is divided into a plurality of shaft parts in a longitudinal direction thereof. The adjacent shaft parts are connected to each other through the joint.

CROSS REFERENCE TO RELATED APPLICATION

This application is based on Japanese Patent Application No. 2008-1103filed on Jan. 8, 2008, the disclosure of which is incorporated herein byreference.

FIELD OF THE INVENTION

The present invention relates to a blower unit for a vehicle forgenerating cooling air for cooling a heat exchanger, such as a radiator,of a vehicle.

BACKGROUND OF THE INVENTION

In a conventional blower unit employed for a heat exchanger having arelatively long core, two axial fans are disposed on a downstream sideof the core with respect to a flow of air, and each of the fans isprovided with a fan motor. That is, the blower unit has the fan motorswith the same number as the number of the fans. In such a case, theentire size and the weight of the blower unit increases. Also, thenumber of parts increases.

To address the above issues, it is proposed to drive the multiple fansby a single motor. In such a case, a driving shaft extending from themotor is connected to rotation shafts of the multiple fans throughgears. The motor is, for example, fixed to a tank of a heat exchanger,which is disposed at an end of a core of the heat exchanger. Such ablower unit is, for example, described in JP-U-62-112470.

SUMMARY OF THE INVENTION

In the blower unit in which the single driving shaft passes throughmultiple gear boxes to be connected to the rotation shafts of themultiple fans through the gears, if displacement or misalignment occursbetween components, such as between the driving shaft and the motor andbetween the driving shaft and the gear boxes, a connecting portionbetween the motor and the driving shaft and the gears receive an excessload. Such an excess load is likely to result in deterioration ofdurability as well as an increase in noise.

The present invention is made in view of the foregoing matter, and it isan object of the present invention to provide a blower unit for avehicle having multiple fans driven by a single motor through gears,which is capable of improving durability and reducing noise.

According to an aspect of the present invention, a blower unit includesa plurality of blowers, a single motor, a driving shaft, gears, gearboxes and a joint. The blowers are arranged in parallel with each otherwith respect to a flow of air passing through a heat exchanger of avehicle. The driving shaft extends from the motor and is connected torotation shafts of the blowers through the gears. The gears are housedin the gear boxes. The driving shaft and the rotation shafts of theblowers are rotatably supported through the gear boxes. The drivingshaft is divided into a plurality of shaft parts in a longitudinaldirection thereof. The adjacent shaft parts are connected to each otherthrough the joint in the longitudinal direction of the driving shaft.

Since the driving shaft is divided into the plurality of shaft parts,and the shaft parts are connected through the joint, displacements ormisalignment between the components, such as between the driving shaftand the motor and between the driving shaft and the gear boxes, areabsorbed. Therefore, durability improves and noise reduces.

For example, the driving shaft has a connecting portion of the shaftparts at a location between the motor and the blower, which is closer tothe motor than the other, and/or a location between the blowers. In sucha case, the joint can be disposed at a location without interfering withthe blowers. Therefore, the size of the joint can be set flexibly. Forexample, it is possible to increase the size of the joint. If the sizeof the joint is increased, the effect of absorbing the displacement ormisalignment is improved.

For example, the driving shaft has connecting portions of the shaftparts at locations adjacent to the gear boxes.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the present invention willbecome more apparent from the following detailed description made withreference to the accompanying drawings, in which like parts aredesignated by like reference numbers and in which:

FIG. 1 is a perspective view of a blower unit for a vehicle, partlyincluding an exploded view, when viewed from a rear location of thevehicle, such as a downstream location with respect to a flow of air,according to a first embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of a blower of the blowerunit, when viewed from a top, according to the first embodiment;

FIG. 3 is a schematic cross-sectional view of the blower unit, whenviewed from a top, according to the first embodiment; and

FIG. 4 is a schematic cross-sectional view of a blower unit, when viewedfrom a top, according to a second embodiment of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS First Embodiment

A first embodiment of the present invention will now be described withreference to FIGS. 1 to 3. In the present embodiment, the presentinvention is exemplarily employed to a blower unit for a vehicle forgenerating cooling air for cooling heat exchangers (not shown), such asan engine coolant radiator and a refrigerant radiator. The enginecoolant radiator is in communication with an engine coolant circuit ofan engine, that is, an internal combustion engine. The engine coolantradiator serves to cool hot engine coolant, which has been heatedthrough the engine. The refrigerant radiator is in communication with adischarge side of a compressor of a refrigerant cycle of a vehicle airconditioner. The refrigerant radiator serves to cool refrigerant, whichhas been discharged from the compressor. In the present embodiment, theengine coolant radiator is disposed behind the refrigerant radiator withrespect to a vehicle front and rear direction.

In the drawing, an up and down arrow, a right and left arrow, and afront and rear arrow denote respective directions when the blower unitis mounted in the vehicle. As shown in FIG. 1, the blower unit generallyhas blowers 1, a fan shroud 2, and a motor device including a singlemotor (motor body) 3. The blowers 1 are disposed in parallel with eachother behind the engine coolant radiator. For example, the blowers 1 arealigned in a longitudinal direction of a core of the engine coolantradiator. The blowers 1 are driven by the single motor 3.

The fan shroud 2 is disposed on a rear side of the engine coolantradiator. The fan shroud 2 is configured to support the blowers 1 and tocover a space between the engine coolant radiator and the blowers 1,thereby to restrict an airflow caused by the blowers 1 from bypassingthe refrigerant radiator and the engine coolant radiator.

The fan shroud 2 includes shroud ring portions 21 and a shroud panelportion 22. The shroud ring portion 21 each have a cylindrical shape,such as a ring shape. The shroud panel portion 22 has a predeterminedshape connecting the rear side of the engine coolant radiator to theshroud ring portions 21. The shroud panel portion 22 forms smooth airpassages from the rear side of the engine coolant radiator to the ringportions 21. In the present embodiment, respective portions of the fanshroud 2, such as the shroud ring portions 21, the shroud panel portion22 and the like, are integrally formed with each other. The shroud panelportion 22 has a rectangular outer shape when projected in a flowdirection of air.

Each of the shroud ring portions 21 provides a Venturi air passage spacetherein. Each of the blowers 1 is disposed in the shroud ring portion 21such that a predetermined clearance is provided between an inner surfaceof the shroud ring portion 21 and radial outer edges of first and secondblades 11 c, 12 c of fans 11, 12. Inside of the shroud ring portion 21,the fans 11, 12 are rotatably supported.

In the present embodiment, since the two blowers 1 are arranged inparallel with each other, the fan shroud 2 has two shroud ring portions21. The two shroud ring portions 21 are arranged in parallel with eachother at locations corresponding to the blowers 1.

The motor 3 is fixed to a rear side of the shroud panel portion 22, suchas on a downstream side of the shroud panel portion 22 with respect to aflow of air, through a bracket 4. The motor 3 is disposed on acenterline passing through centers of the shroud ring portions 21.

Next, a structure of the blowers 1 will be described in detail.

As shown in FIG. 2, each of the blowers 1 has contra-rotating fans 11,12, such as a first axial fan 11 and a second axial fan 12. The firstaxial fan 11 and the second axial fan 12 are disposed in series withrespect to the flow of air. That is, the first axial fan 11 and thesecond axial fan 12 are arranged such that first and second rotationshafts 11 a, 12 a thereof are aligned with each other. The first axialfan 11 is disposed on a front side of the second axial fan 12 withrespect to the vehicle front and rear direction. That is, the firstaxial fan 11 is disposed upstream of the second axial fan 12.

The first and second axial fans 11, 12 are disposed to rotate inopposite directions, but the flow directions of the air caused by thefirst and second axial fans 11, 12 are the same. A component of turningflow generated at an outlet of the first axial fan 11 in acircumferential direction is cancelled by the contra rotation of thesecond axial fan 12. Therefore, kinetic pressure of the turning flowgenerated at the outlet of the first axial fan 11 is recovered as staticpressure. Because the static pressure is larger than static pressuregenerated in a general series of fans, the volume of air passing throughthe heat exchangers can be increased.

The first axial fan 11 has a first boss part 11 b and first blades 11 cradially extending from the first boss part 11 b. The first boss part 11b has a tubular shape with a closed end. Thus, the first boss part 11 bhas a substantially U-shaped cross-section. The first boss part 11 bincludes a first bottom wall 11 d having a circular shape and a firstside wall 11 e extending from an edge of the first bottom wall 11 d. Thefirst side wall 11 e is substantially perpendicular to the first bottomwall 11 d. The first rotation shaft 11 a extends from the center of thefirst bottom wall 11 d. The first blades 11 c extend from an outersurface of the first side wall 11 e.

Likewise, the second axial fan 12 has a second boss part 12 b and secondblades 12 c radially extending from the second boss part 12 b. Thesecond boss part 12 b has a tubular shape with a closed end. Thus, thesecond boss part 12 b has a substantially U-shaped cross-section. Thesecond boss part 12 b includes a second bottom wall 12 d having acircular shape and a second side wall 12 e extending from an edge of thesecond bottom wall 12 d. The second side wall 12 e is substantiallyperpendicular to the second bottom wall 12 d. The second blades 12 cextend from an outer surface of the second side wall 12 e.

The first and second axial fans 11, 12 are arranged such that openingsof the first and second boss parts 11 b, 12 b are opposed to each other.In other words, the first and second axial fans 11, 12 are arranged suchthat ends of the first and second side walls 11 e, 12 e are opposed toeach other.

Driving gears 32 are fixed on a driving shaft 31, which extends from themotor 3, at locations corresponding to the two blowers 1. The drivinggears 32 are, for example, bevel gears.

In each blower 1, the first and second fans 11, 12 are arranged suchthat the first and second rotation shafts 11 a, 12 a are perpendicularto the driving shaft 31. A first driven gear 11 f is fixed to an end ofthe first rotation shaft 11 a. A second driven gear 12 f is fixed to anend of the second rotation shaft 12 a. The first and second driven gears11 f, 12 f are engaged with the driving gear 32, respectively. Thus, adriving force generated from the motor 3 is transmitted to the first andsecond rotation shafts 11 a, 12 a through the driving shaft 31 and thegears 32, 11 f, 12 f, and hence the first and second rotation shafts 11,12 are rotated in the opposite directions. The first and second drivengears 11 f, 12 f can be bevel gears, for example.

A gear box 5 is disposed in a space provided between the first andsecond boss parts 11 b, 12 b, for example. The first and second rotationshafts 11 a, 12 a are rotatably supported by the gear box 5 throughfirst and second bearings 11 g, 12 g. The gear box 5 houses the firstand second driven gears 11 f, 12 f as well as the driving gear 32. Also,the gear box 5 rotatably supports the driving shaft 31 through a bearing33, similar to the first and second rotation shafts 11 a, 12 a.

As shown in FIG. 1, the gear boxes 5 are supported by stays 23 that areextended in a horizontal direction, such as in a longitudinal directionof the driving shaft 31, and fixed to the fan shroud 2. In the presentembodiment, for example, two stays 23 are arranged parallel to eachother and support upper and lower ends of the gear boxes 5.

FIG. 3 shows a schematic cross-section of the blower unit when viewedfrom a top. In FIG. 3, an internal structure of the gear box 5 is notillustrated. In the present embodiment, the fan shroud 2 has the twoshroud ring portions 21 aligned in the longitudinal direction of thedriving shaft 31. Hereinafter, one of the shroud ring portions 21, whichis closer to the motor 3 than the other, is referred to as a firstshroud ring portion 21A, and the other, which is further from the motor3 than the first shroud ring portion 21A, is referred to as a secondshroud ring portion 21B.

As shown in FIG. 3, the driving shaft 31 is divided into three shaftparts 310 in the longitudinal direction thereof. Specifically, thedriving shaft 31 is divided at a first location between the motor 3 andthe first shroud ring portion 21A and a second location between thefirst shroud ring portion 21A and the second shroud ring portion 21B,that is, between the two blowers 1.

Joints 6 are provided between the adjacent shaft parts 310. The adjacentshaft parts 310 are connected to each other in the longitudinaldirection of the driving shaft 31 through joints 6. That is, the joints6 are located between the motor 3 and the first shroud ring portion 21Aand between the first shroud ring portion 21A and the second shroud ringportion 21B. For example, each of the joints 6 is made of a metal, andhas a substantially cylindrical shape having an axis coincident with alongitudinal axis of the driving shaft 31.

The driving shaft 31 extends in an alignment direction of the twoblowers 1, that is, in a vehicle width direction corresponding to aright and left direction. The single driving shaft 31 is constructed byconnecting the three shaft parts 310 with the two joints 6 in thealignment direction of the two blowers 1.

As discussed above, the driving shaft 31 includes the multiple shaftparts 310, and the multiple shaft parts 310 are connected through thejoints 6. As such, displacement or misalignment between the drivingshaft 31 and the motor 3 and between the driving shaft 31 and the gearboxes 5 can be absorbed. Accordingly, durability of the blower unitimproves, and noise reduces.

In a case where the joints 6 are located between the opposed first andsecond blades 11 c, 12 c of the blower 1, it is necessary to provide apredetermined clearance between the first and second blades 11 c, 12 cto prevent the joint 6 from contacting the first and second blades 11 c,12 c. In such a case, the dimension of the blower 1 is increased in thevehicle front and rear direction, depending on the size of the joint 6.Further, if a space for mounting the blower unit is limited in an enginecompartment of the vehicle, it is necessary to reduce the size of thejoints 6. In such a case, it is difficult to sufficiently achieve theeffect of absorbing the displacement or misalignment.

In the present embodiment, on the other hand, the driving shaft 31 hasconnecting portions of the adjacent shaft parts 310 at the firstlocation between the motor 3 and the first shroud ring portion 21A andthe second location between the first shroud ring portion 21A and thesecond shroud ring portion 21B. Namely, the joints 6 are disposed inareas without interfering with the first and second blades 11 c, 12 c ofthe blowers 1. Accordingly, the size of the joints 6 can be flexiblydecided. For example, the size of the joints 6 can be increased withoutconsidering the clearance between the first and second blades 11 c, 12c. Therefore, the effect of absorbing the displacement or misalignmentcan be sufficiently achieved. As a result, the durability furtherimproves, and the noise further reduces.

Second Embodiment

A second embodiment of the present invention will be described withreference to FIG. 4. Hereinafter, parts similar to the first embodimentare designated with the same reference numbers, and a descriptionthereof is not repeated.

FIG. 4 shows a schematic cross-section of the blower unit of the secondembodiment when viewed from a top. In FIG. 4, an internal structure ofthe gear box 5 is not illustrated. Hereinafter, one of the blowers 1,which is closer to the motor 3 than the other, is referred to as a firstblower 1A, and the other, which is further from the motor 3 than thefirst blower 1B, is referred to as a second blower 1B.

As shown in FIG. 4, the driving shaft 31 is divided into five shaftparts 310 in the longitudinal direction thereof. Specifically, thedriving shaft 31 is divided at a first location between the motor 3 andthe first shroud ring portion 21A, second and third locations, which areon axially opposite sides of the gear box 5 of the first blower 1Awithin the first shroud ring portion 21A, and a fourth location adjacentto the gear box 5 of the second blower 1B within the second shroud ringportion 21B. The second location is adjacent to the gear box 5 on a sidecloser to the motor 3, and the third location is adjacent to the gearbox 5 on an opposite side further from the motor 3. The fourth locationis adjacent to the gear box 5 of the second blower 1B on a side closerto the motor 3.

The joints 6 are provided between the adjacent shaft parts 310. Theadjacent shaft parts 310 are connected to each other through the joints6. In the present embodiment, the joints 6 are disposed at the firstlocation between the motor 3 and the first shroud ring portion 21A, thesecond and third locations, which are on axially opposite sides of thefirst and second boss parts 11 b, 12 b of the first blower 1A, and thefourth location, which is adjacent to the first and second boss parts 11b, 12 b of the second blower 1B on a side closer to the motor 3. Thesecond and third locations are outside of the first and second bossparts 11 b, 12 b within the first blower 1A. The fourth location isoutside of the first and second boss parts 11 b, 12 b within the secondblower 1B.

Accordingly, the driving shaft 31 extending in the alignment directionof the first and second blowers 1A, 1B, such as in the vehicle widthdirection, is constructed by connecting the five shaft parts 310 throughthe four joints 6.

Therefore, displacement or misalignment between the driving shaft 31 andthe motor 3 and between the driving shaft 31 and the gear boxes 5 areabsorbed. Accordingly, the durability of the blower unit improves, andthe noise reduces.

Other Embodiments

In the above embodiments, the present invention is employed to theblower unit in which the two blowers 1 are aligned in the longitudinaldirection of the driving shaft 31. However, the present invention can beemployed to a blower unit in which a single blower is arranged, or threeor more than three blowers are arranged.

Further, the connecting portions of the shaft parts 310 are not limitedto the above discussed locations. Also, the number of the connectingportions of the shaft parts 310 and the number of the joints 6 are notlimited to the above described numbers.

For example, in the first embodiment, the driving shaft 31 may have aconnecting portion of the shaft parts 310 at least one of between themotor 3 and the first shroud ring portion 21A and between the first andsecond shroud ring portions 21A, 21B. As another example, in the secondembodiment, the driving shaft 31 may have further another connectingportion of the shaft parts 310 between the first and second shroud ringportions 21A, 21B.

The blower 1 is not limited to have the contra-rotating fans. The blower1 may have a single axial fan.

In the above embodiments, the motor 3 is fixed to the fan shroud 2through the bracket 4, and the gear boxes 5 are fixed to the fan shroud2 through the stays 23. However, the motor 3 and the fan shroud 2 may befixed in various other ways. For example, the motor 3 and the gear boxes5 can be directly fixed to the fan shroud 2, respectively.

Additional advantages and modifications will readily occur to thoseskilled in the art. The invention in its broader term is therefore notlimited to the specific details, representative apparatus, andillustrative examples shown and described.

1. A blower unit for generating air passing through a heat exchanger ofa vehicle, the blower unit comprising: a plurality of blowers arrangedin parallel with each other with respect to a flow of air passingthrough the heat exchanger, the blowers having rotation shafts; a singlemotor; a driving shaft extending from the motor, the driving shaft beingdivided into a plurality of shaft parts in a longitudinal directionthereof; gears connecting the driving shaft and the rotation shafts ofthe blowers; gear boxes housing the gears therein, the gear boxessupporting the driving shaft and the rotation shafts to be rotatable;and a joint disposed between adjacent shaft parts and connecting theadjacent shaft parts in the longitudinal direction of the driving shaft.2. The blower unit according to claim 1, wherein the driving shaft has aconnecting portion of the shaft parts at least one of between the motorand one of the blowers, which is located closer to the motor than theother, and between adjacent blowers.
 3. The blower unit according toclaim 1, wherein the driving shaft has connecting portions of the shaftparts at locations adjacent to the gear boxes.
 4. The blower unitaccording to claim 1, further comprising: a fan shroud including aplurality of shroud ring portions aligned in the longitudinal directionof the driving shaft, wherein the blowers are correspondingly disposedin the shroud ring portions, each of the blowers has a first axial fanand a second axial fan, the first axial fan has a first boss part and aplurality of first blades radially extending from the first boss part,the second axial fan has a second boss part and a plurality of secondblades radially extending from the second boss part, the first axial fanand the second axial fan are opposed to each other with respect to thedriving shaft, and the gear box is disposed in a space provided betweenthe first and second boss parts.
 5. The blower unit according to claim4, wherein the driving shaft is divided into the shaft parts at a firstlocation between the motor and one of the shroud ring portions, which islocated closer to the motor than the other, and at a second locationbetween adjacent shroud ring portions.
 6. The blower unit according toclaim 4, wherein the driving shaft is divided into the shaft parts at afirst location between the motor and a first shroud ring portion, secondand third location, which are adjacent to the first and second bossparts of a first blower on axially opposite sides of the first andsecond boss parts within the first shroud ring portion, and a fourthlocation adjacent to the first and second boss parts of a second blowerwithin a second shroud ring portion, the first blower being one of theplurality of blowers and located closer to the motor than the other, thesecond blower being another one of the plurality of blowers and locatedfurther from the motor than the first blower, the first shroud ringportion being one of the plurality of shroud ring portions and locatedcloser to the motor than the other, the second shroud ring portion beinganother one of the plurality of shroud ring portions and located furtherfrom the motor than the first shroud ring portion.